The astronomers found an "X-ray mass" only a tenth of the mass found using the gravitational lens method.

天文学家发现“X射线估算的质量”仅有“引力透镜”方法估算的质量的十分之一。

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In this method, when one star passes in front of another, as seen from Earth, the nearer star's gravity ACTS like a lens, bending and magnifying the more distant star's light.

当天文学家用这种方法从地球上观测到一颗恒星在另一颗恒星前“走过”时，距地球较近的这颗恒星的重力就如同一个镜头，将较远的那颗恒星的光弯曲并放大。

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A method of making the Fresnel lens is described.

本文还描述了制造菲涅耳透镜的方法。

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Then he discovered a new Japanese method of cutting diamonds: When viewed under a low-magnification (3x) lens, the stone refracted light in such a way as to give off a pattern of eight heart-shaped sparkles at the bottom of the diamond and eight arrow-shaped fire-bursts through the top--hence the name "hearts-and-arrows" diamonds.

FORBES: Stones on fire